Means for eliminating roll of tunneling shield

ABSTRACT

A tunnel shield is pushed through the ground by hydraulic rams, but has a tendency to rotate and, unless corrected, the forward support for the spoil conveyor and other equipment gets out of proper alignment and there are other undesirable results. To restore alignment an interior shell is rotatably mounted inside the shield and provides the forward support for the aforementioned equipment. Means is provided to rotate the interior shell relative to the shield so as to restore the interior shell to level position whenever the shield has rotated.

United States Patent [191 Colson MEANS FOR ELIMINATING ROLL OF TUNNELINGSHIELD [751 Invenwfl eese Qeanrsq emefia ilihfl [73] Assignee:Engineering Field Services, San Rafael, Calif.

[22] Filed: Jan. 26, 1972 [21] App]. No.: 220,756

[52] US. Cl. 61/85 [51] Int. Cl. E0lg 5/14 [58] Field of Search 61/85,43, 42, 44, 61/45, 84

[56] References Cited UNITED STATES PATENTS 3,404,920 10/1968 Tabor61/85 X 3,427,813 2/1969 Hayes 61/85 FOREIGN PATENTS OR APPLICATIONS1,236,548 3/1967 Germany 61/85 3,763,657 Oct. 9, 1973 PrimaryExaminer-J. Karl Bell Att0rney.lu1ian Caplan 3 Claims, 3 Drawing FiguresMEANS FOR ELIMINATING ROLL OF TUNNELING SHIELD This invention relates toa new and improved means for eliminating roll of tunneling shields. Moreparticularly, the invention relates to a means for restoring to verticalthe forward support of conveyors and other equipment which are installedin the interior of tunnel shields which are driven through earth byhydraulic rams.

A principal object of the present invention is to provide means tosupport or anchor the forward end of equipment used in tunnelconstruction in such manner that a permanently horizontal support isprovided regardless of rotation of the tunnel shield. It will beunderstood that spoil conveyors, shield driving control equipment andthe like is located in the tunnel shield, and for proper alignment andoperation it is very desirable that the support be kept permanentlyhorizontal. In practice, however, it has been found that shields tend torotate as a reaction to the driving forces, and this rotation causesmisalignment and other failures of the conveyor and other equipment. Thepresent invention has for its principal purpose the avoidance of suchmisalignment.

Heretofore, surveyingof the tunnel shield has been necessary to revealrotation. In previous practice, elaborate means were required to correctrotation and such means are avoided in accordance with the presentinvention. Further, correcting the rotation of the shield has requiredsuspension of normal tunneling activities which in some instancesseriously delays completion of the tunneling. Such costly delays arelikewise eliminated by this invention.

In order to detect rotation of the tunnel shield, it is necessary tosurvey; and because of the fact that equipment which is installed insidetunnels interferes with surveying, such surveying has been extremelydifficult. Offset methodsof surveying have been utilized. The presentinvention makes such surveying largely unnecessary. A simple spiritbubble, properly located in the interior shell, is all that is requiredto detect rotation and to determine when the rotation has beencorrected. In one method used to correct alignment of the tunnel shieldthroughout its tunneling operations, a set of targets is placed and alaser beam is used in conjunction with these targets to keep the tunnelshield in its correct alignment both horizontally and verticallythroughout its passage through the earth. When the shield rotates, itdestroys the relative position of the targets in relation to the one.

Other objects of the present invention will become apparent upon readingthe following specification and referring to the accompanying drawingsin which similar characters of reference represent corresponding partsin each of the several views.

In the drawings:

FIG. 1 is a schematic side elevational view of a tunnel shield brokenaway to reveal interior construction.

FIG. 2 is a vertical sectional view taken substantially along the line2--2 of FIG. 1.

FIG. 3 is an enlarged sectional view taken substantially along the line33 of FIG. 2.

A conventional tunnel shield 1 l is a cylindrical member having abeveled forward end 12 which is pushed through relatively soft earth todefine the tunnel bore 13. conventionally, liners 14 are installed atthe rear of the shield l 1, said liners comprising pluralities ofarcuate sections which are bolted together and eventually form theinterior of the tunnel. Since the shield 11 is of larger diameter thanthe exterior of the liners 14, a slight gap is created between theexterior of the liners 14 and the bore 13, and this is ordinarily filledwith grout, gravel or some other 'material.

The liners 14 ordinarily 'have radial flanges 16 by which the varioussections are bolted or otherwise connected together edge to edge. Theflanges 16 are used as a means for thrusting the shield 11 forwardly asthe digging of the tunnel progresses. Thus, a plurality of hydraulicrams is located pivotted to brackets with the shield 11, and therearward extending rods 17 of these rams provided with feet 18 whichengage the flanges 16. Hydraulic force applied to the rams causes theshield 11 to be pushed forward, the liners 14 providing the anchor orsupport against which the shield 11 is pushed. It has been found inactual practice that this means of propelling the shield 11 issatisfactory except for the fact that the reaction forces tend to causethe shield 11 to rotate at times, and the extent and frequency of suchrotation is unpredictable. A great amount of equipment is installedinside the shell 11,

and the operator of the hydraulic controls is also located there. Amongthe equipment are conveyors 19 which convey the spoil from the floor ofthe bore 13 to the rear where it is deposited onto cars or is otherwiseconveyed away. It is quite important that all this equipment bemaintained level; but if the shield 11 is not maintained againstrotation, then very expensive time consuming realignment procedures havebeen required. These procedures are unnecessary in accordance with thepresent invention.

An interior shell 21 is mounted approximately midway of the length ofshield 1 1 and this interior shell has a lesser length than the shield.Pluralities of rollers 22 or other bearing means are interposed betweenthe shield 11 and the interior shell 21 to permit relative rotationthereof. A ring gear 23, or segments thereof, are mounted fixed relativeto shield 11. A plurality of pinions 24 turned by hydraulic or electricmotors 26 are supported so that they are fixed relative to interiorshell 21. By energizing motors 26 in either direction, the interiorshell 21 may be turned relative to shield 11. The rams (not shown) whichmove rods 17 are located fixed to shell 21. Hence, the forward thrust ofthese rams is transmitted by means of annular front support ring 28 onthe forward end of shell 21 against a matching annular push ring 31which is fixed to shield l 1 and strengthened by gussets 32. When therams push forward, ring 28 pushes against the ring 31 and forces theshield 11 forwardly, the thrust being absorbed by flanges 16 or one ofthe liners 14 and transmitted by that liner rearwardly to the otherliners. To prevent the friction of rings 28 and 31 from preventingreverse rotation of the shell 21, back-off rams 23, or springs or othermeans are fixed to shell 21 and project through apertures in forwardsupport ring 28 to bear against push ring 31. Thus, after the maindriving rams have been deenergized, it is possible by means of theback-off rams 33 to push the shell 21 rearward away from push ring 31 topermit the motors 26 to turn shell 21 to restore the original horizontalposition thereof regardless of the position in shield 11.

It is apparent that if there is a tendency for shield 11 to rotate, theinterior shell 21 will rotate and the shield itself will be pushedforward in its proper vertical position. In some cases, however, thefriction between the rings 28 and 31 will cause the shield 11 as well asthe shell 21 to rotate. Rather than it being necessary to restore theshield 11 to its proper position relative to the vertical, it can beleft in its misaligned position without further difficulty, and theinterior shell 21 restored to its proper relationship to the vertical,thereby preserving the alignment of the equipment which is all anchoredto the interior shell.

What is claimed is:

1. In a tunneling machine a shield, a shell rotatably supported withinsaid shield, rotation means cooperable between said shield and saidshell for rotating said shell relative to said shield comprising a ringgear on said shield, a pinion rotatably mounted on said shell meshingwith said ring gear, a motor for revolving said lot pinion, and drivemeans for driving said shield and shell together in the same directionas the axis of their relative rotation comprising a plurality of ramsfixed to said shell and having rods extending rearwardly of both saidshell and shield and having means at their ends opposite said rams foranchoring said rods to the wall of a tunnel.

2. In a machine according to claim 1 a first annular ring on the forwardend of said shell and a second annular ring fixed to said shieldimmediately forward of said first ring to transmit thrust of said shellto said shield.

3. A machine according to claim 2 which further comprises back-off meansfor forcing said rings apart after completion of forward thrust of saidshield.

1. In a tunneling machine a shield, a shell rotatably supported withinsaid shield, rotation means cooperable between said shield and saidshell for rotating said shell relative to said shield comprising a ringgear on said shield, a pinion rotatably mounted on said shell meshingwith said ring gear, a motor for revolving said pinion, and drive meansfor driving said shield and shell together in the same direction as theaxis of their relative rotation comprising a plurality of rams fixed tosaid shell and having rods extending rearwardly of both said shell andshield and having means at their ends opposite said rams for anchoringsaid rods to the wall of a tunnel.
 2. In a machine according to claim 1a first annular ring on the forward end of said shell and a secondannular ring fixed to said shield immediately forward of said first ringto transmit thrust of said shell to said shield.
 3. A machine accordingto claim 2 which further comprises back-off means for forcing said ringsapart after completion of forward thrust of said shield.